1. Field of the Invention
The invention relates to a novel seam-forming apparatus for connecting building panels in a continuous seam along adjacent side edges of two building panels in the construction of a building or like structure.
2. Prior Art and Background
It is known to construct continuous arch metal buildings with adjacent curved building panels which are seamed together at their adjacent edges. Such a system is described, for example, in U.S. Pat. No. 4,505,084 and U.S. Pat. No. 5,249,445.
In connection with seaming panels for such metal buildings, seaming devices have been used. Such a device is disclosed, for example, in U.S. Pat. No. 4,470,186 which is hereby incorporated by reference as if fully set forth herein. The seaming device connects or seams together the side edge portions of adjacent panels.
An apparatus referred to as a panel machine produces structural panel members using a roll forming process such as described in U.S. Pat. No. 4,505,084. Incorporated in one edge of each panel is a hook portion and on the opposite edge is a hem portion. The hem portion is designed to fit underneath and inside of the hook portion of an adjacent panel resulting in an interlocking feature for joining the panels together. The panels themselves may be curved or straight and may have both straight and curved portions.
Past seamers have usually only been capable of seaming either straight panel portions or curved panel portions. Such seamers are not able to seam panels that are both straight and curved. When attempting to utilize such a seamer on panels with both curved and straight portions, the seaming apparatus tends to "walk off" or dislodge from the seam particularly in transition areas where the panel changes from straight to curved or vice versa. In addition, such seamers were prone to cause damage to the panel and the finish of the panel, particularly in the transition regions.